Doloto: The Power of AJAX without Its Headaches (a Microsoft Research Project)

Doloto is an AJAX application optimization tool, especially useful for large and complex Web 2.0 applications that contain a lot of code, such as Bing Maps, Hotmail, etc. Doloto analyzes AJAX application workloads and automatically performs code splitting of existing large Web 2.0 applications. After being processed by Doloto, an application will initially transfer only the portion of code necessary for application initialization.

The rest of the application’s code is replaced by short stubs—their actual function code is transferred lazily in the background or, at the latest, on-demand on first execution. Since code download is interleaved with application execution, users can start interacting with the Web application much sooner, without waiting for the code that implements extra, unused features.

Doloto reduces the size of initial application code download by hundreds of kilobytes or as much as 50% of the original download size. The time to download and begin interacting with large applications is reduced by 20-40% or dozens of seconds as shown below, depending on the application and wide-area network conditions.